suggestion for new wide angle lens?

Hi all, I have the 16-50 pentax lens for my K5 and it is not working properly. Since I am travelling for several weeks I will have to wait until I get home to get it fixed. I would like to get another lens for the rest of the trip for scenic shots and I was thinking of trying a prime lens for a change as opposed to the zoom. Which lens would you suggest a 21mm or something different? I was looking for something in the wide angle range. I am also planning to get the 50-135 lens.